The present invention relates to a process for emitting and receiving binary data and to a circuit or interface for implementing this process.
More particularly, the present invention relates to the field of digital telephone and to an interface circuit permitting, from a flow of input data words regularly arriving according to a clock rate, to transmit frame grouped data, each frame comprising n data words from the first flow and accompanying words useful for synchronizing and identifying the frames. The system has to operate in such a way that the transmission of n data words in the second flow with the additional accompanying words has the same duration as the reception of n data words from the first incident flow.
The invention also aims at providing for a circuit symmetrical to the above-mentioned circuit, that is, an interface receiving frames and sending back a continuous flow of data words without the accompanying words.
One object of the present invention is to provide for such a process which is particularly simple to implement, realizable in the form of an integrated circuit, and which avoids any loss of information once the synchronization initial operations in the interface have been carried out.
In order to achieve this object and others, the present invention provides for a process to convert a first flow of data words supplied according to a first clock rate into a second flow of data comprising, inside successive frames, a sequence of n data words of the first flow and accompanying data, the duration of each frame of the second flow being equal to the duration of n data words in the first flow, this process comprising the following steps:
storing the successive data words of the first flow in an input register, PA1 as soon as the register is full, writing its contents in one of p intermediate registers, PA1 sequentially reading the p intermediate registers into an output register, and PA1 skipping, at the start of the following frame, one read operation until a suitable synchronization, which will then be maintained during the subsequent frames, is obtained.